Even if you assume that technological level four analogues are prototypes, they were mostly rather effective: the Luger was accurate if complicated, the Colt Semiautomatic tended to stop people dead in their tracks, and the Mauser was better than nothing.

The Fifties probably is the last time you really had anything revolutionary in gun design, and everything since then had been incremental improvements, with the autopistol probably equivalent to the Browning High Power, manufactured in the mid Thirties; at best technological level five.

Body Pistol

Taken as presented, rather than Bond's Walther Polizeipistole Kriminalmodell, maybe a composite carbon fibre receiver and barrel? That would certainly justify the technological level eight.

Revolver

You had them at technological level three, at the end of the sixteenth century; reloading seems a pain. Let's call it a prototype, with Samuel Colt's making the first viable mass produced models at technological level four.

Snub Pistol

I tend to think the human variant is likely to look closer to this, without a lot of the scifi frills.

3D printed guns (and other items) today are a far cry from what actual atom-by-atom nanoassembly will make possible. The only limit on durability then will be the material limits of the elements involved.

Pistols tend to have to wait a technological level before they get manufactured, which doesn't seem quite right.

Anyway, there probably is an advanced version of the semi automatic pistol; I'm inclined to think it would be available at technological available at nine, but ten seems safe. There probably would have a three shot burst fire feature. Damage potential would still be three dee minus three.

This weapon mounts six full-length barrels, each of which can be loaded with a three-round superposed-load cartridge. The 9 mm, 10 gram rounds have a muzzle velocity of 400 meters per second. Rounds may be fired individually or in two or three round bursts, at selectable rates of fire from 20 to 800 rounds per second; at maximum burst rate, the rounds are spaced just 50 cm apart. Ignition is through electrical induction, powered by a battery in the grip. Because of the six full-length barrels, it is a heavy pistol, which reduces perceived recoil in burst fire.

Four and six roun per barrel versions exist, but are very uncommon except in Aslan versions.

The reason to fire superposed rounds at highest speed is that you three rounds that you put three rounds on the same point on the target. The first smacks the armor and weakens it, the second break through, and the third hurts the target.

Math: If the target is walking at 3 miles per hour (5 km/h) relative to the line of fire. That's about 1.3 meters per second. At 800 rounds per second, bullets arrive 1.25 milliseconds apart, during which the target has moved about 1.7 mm. (That assumes a perfectly steady aim, without flinch or barrel rise, so actual results may vary.)

The reason to fire superposed rounds at low speeds (still faster than most ordinary auto-fire) is the same as for a burst from an automatic rifle: better chance to hit.

Metal Storm went into liquidation a few years ago. I guess not enough people agreed it was a good idea worth investing in.

The HK G11 had a similar idea with a very high rate of fire using a rotating breach. There were issues with a few things (google it for more info) I think one of which was the "engineers" didn't think you needed an ejection port. Good luck ejecting a round to make the weapon safe for cleaning.